Active Directory Expanding Record Performance Issues - Take 2 from 2018

This was asked previously answered with a not-so-useful response so I'll re-post in hope of something other than "don't expand records from AD" 😉.

I connected to an AD user base with Power BI (no record expansions...yet) and the query loads in seconds on my desktop. Now, the mystery: with the expansion of 1 record (Person.sn), it times out loading 43k records (never ending refresh... over a weekend it ran).

Questions...

1. what is happining with AD in the expansion process?
2. Are 43k requests being made in the background for every expansion?
3. Is there a way to narrow the initial AD request to the records I want without downloading the world?
4. Will "Table.Buffer" help here? (doesn't seem to)

Thanks! 

PS. Saw this post from 2018 but the response fell short of a solution really.

https://community.powerbi.com/t5/Desktop/Active-Directory-Expanding-Record-Performance-Issues/td-p/4...